These documents are designed to be printed double-sided, with the even pages going on the backs of the odd ones. It is for this reason that the photographs appear on the right (odd) pages, while their captions are on the left (even) ones: printing out a large graphic on both sides of a sheet of ordinary paper on an inkjet printer is likely to cause the paper to ripple because it soaks up much of the ink, which is avoided this way.
Printing double-sided will likely require a bit of experimentation to make sure you get it right, but because of the many different types of printer in use, no definite, all-encompassing instructions can be given here. Still, some guidelines are given below that will apply to many printer models, but if you have never tried printing double-sided, do some tests first before you try a whole document.
Most inkjet printers fall into this category: when the paper comes out of the printer, it does so with the printed side facing upward.
To print double-sided with this kind of printer, first print out only the even pages, in reverse order. Then put them back into the feed tray, with the blank side up but so that the tops of the pages will be fed into the printer first. Now print out just the odd pages, but in normal (non-reverse) order. Once you're done, you have all the pages in the correct order.
On some printers, especially laser printers, the pages come out with the printed side facing down. With these, it is easiest to first print the odd pages in reverse order. Take them from the out tray, and place them in the feed tray with the blank side down, and so that the tops of the pages will go into the printer first. Then print the even pages, but in normal (non-reverse) order.
When figuring out how to put the paper back into the printer, the following points are what you need to pay attention to.
Should you have access to a printer that can print double-sided as standard, just switch on that option and print the whole document in one go.
If you print to A4 paper (that is, if you live outside of North America), you should not have your PDF viewer resize the page to fit the paper, unless you notice a problem with parts of the photos or text disappearing in the margins.
For those using Letter-size paper, you should set your PDF viewer fit the page to the paper size, else you will probably miss the bottoms of most pages.